does anyone happen to kno the correct measurements needed to fabricate myself a custom exauhst...or possibly a pic of your gst exauhst or underside of your car....and my car is pretty stock as yu all kno,so next question is 2.5 or 3"???

 

if you are staying under 400hp I would get 2.5 inch.

 

for you to fab ur own exhaust you have to take your own measurements, i always go 3" on turbo apps, its kind of a measure as you go kind of thing. make sure you use mandrel bends, flanges, and a flex pipe. i have seen so many people put systems together without and it just becomes a pain in the ass. if you need any exhaust building advise lemme know, i build all my exhaust systems for all my cars, plus i built systems for numerous other cars....

 

whats the diff between mandrel bending and other methods?? and also about how many ft of pipes will i need to play it safe??

 

Mandrel Myths-Mandrel Bending vs Pressure Bending

 

i gotta see the car but it usually takes like 6 j bends, a 4ft straight, 2 pairs of flanges, a flexpipe, a resonator, and a muffler to have all the parts u need to put a turbo back system together. Plus all the hanger hardware. A mandrel bend is a bend that maintains the same diameter throughout the entire bend, the bends you see at the autoparts store and muffler shops are ususally crush bends, meaning the diameter in the bend is drastically smaller than that of the straights. who is welding your pipes up for u?